3D printing is a rapid prototyping technology. The data of 3D model file produced by designer can be inputted to 3D printer for applying molding materials such as metal or plastic in powder shape etc. to print layer by layer and form a 3D entity model. Such technologies in the industry are also known as additive manufacturing, and have the advantage to form object in any shape.
Due to the rapid development and the importance of the 3D printing technology, a variety of 3D printing technologies are developed according to different needs of customers by manufacturers. However, the conventional 3D model files are mostly in unprotected state. When these files are published to the Internet for users, any user can read the data of these files by 3D printing system and then print and generate the 3D entity model. Therefore results of the work of the designer and assets of the owner are not given appropriate protection.
The conventional methods for protecting the 3D model file are encrypting the file so that the unauthorized user cannot entirely get the contents of the 3D model file. As shown in China patent application publication No. CN102855657 discloses a method and device for 3D object protection by transformation of its points. The invention is directed to a method of protecting a graphical object and comprises the following step: obtaining a protected graphical object; generating a translation vector and transforming the point by adding the point to the translation vector; and outputting the protected graphical object. In one preferred embodiment, the graphical object is a three-dimensional object.
However, the conventional method and equipment for encrypting the 3D model file, in practical application, the visual appearances of the original 3D model and the encrypted 3D model are different. Furthermore, makes it difficult to specifically recognize the original shape of the encrypted 3D model. While providing a preview image of the encrypted 3D model to a buyer, it would be hard for the buyer to decide whether to buy the 3D model or not.